Field of the Invention
The present invention relates to a digital rights management (DRM) system and a service method thereof, and more specifically, to a cloud enterprise digital rights management (E-DRM) system and a service method thereof, which configures an E-DRM system for document security as a cloud environment and provides a service thereof.
Background of the Related Art
With the popularization of the Internet and the advancement in information communication techniques, use of digital contents is generalized. By the nature of digital technology, the digital contents maintain a quality state the same as that of an original copy although they are indefinitely copied. In addition, information thereof is easy to change, and the digital contents may be rapidly distributed into a wide area through a high-speed network. Therefore, management of copyright on the digital contents is very important, and, for these reasons, a variety of digital contents protection techniques are released in relation to creating and manufacturing, storing and managing, and protecting and distributing the digital contents, and providing digital contents service. A representative digital contents protection technique includes copy protection, conditional access system (CAS), digital rights management (DRM) and the like. The copy protection technique for protecting illegal copy of digital contents transmitted between devices is disadvantageous in that the copy protection can be applied only within a limited scope and cannot control various sorts of rights, and the CAS for granting a right for receiving broadcasting contents only to permitted viewers is disadvantageous in that it may control only the right for receiving the broadcasting contents. Contrarily, the DRM which may control various kinds of rights and support various types of formats is recognized as being appropriate as a contents protection technique in a digital convergence environment.
The DRM is a technique and service for protecting the profits and rights of digital right holders, and although the DRM is once regarded as being limited only to multimedia contents such as images, music, videos, games and the like, all sorts of contents may be a target of the DRM, and recently, the DRM technique is used to protect even internal information of an enterprise.
In order to protect illegal use or copy of digital contents, infringement of copyright or the like committed by a third party, the DRM uses a method of distributing encrypted digital contents and granting a decoding right for using the contents when the contents are executed only to authorized users. A dedicated program for discriminatingly granting a right to read, copy, store, output or edit according to the privilege of a user is installed and used in a user PC as a plug-in program or in a separated installation method so that only authorized users may view the encrypted contents. In addition, the dedicated program installed in the user PC performs a control and management function for allowing only authorized users to use the contents after confirming the privilege of the users while communicating with a DRM server.
The DRM may be largely divided into a commercial DRM (C-DRM) for protecting commercial value of digital contents and an enterprise DRM (E-DRM) for protecting internal document resources of an enterprise, and although the C-DRM and the E-DRM may be regarded as being similar to each other from the viewpoint of privilege control, their implementation techniques and use environments are quite different from each other. That is, since usage of the C-DRM is for protecting commercial value of digital contents, the C-DRM is used to allow a permitted user to use the digital contents and to prevent the digital contents from being copied by controlling a multimedia player or a playback program which plays back videos, audios and the like. On the other hand, since the purpose of the E-DRM is to protect internal document resources of an enterprise, the E-DRM allows only an authorized user to access the internal document resources and is used to control information through the control of a document edit program. While the C-DRM is regarded as being important with the advancement in the digital contents industry, as the factors which threaten security also increase with the improvement of technical skills, the E-DRM for minimizing the damage and loss of intellectual properties incurred by unauthorized behaviors becomes more important.
Existing E-DRM security techniques use a method of relying on control of software installed in a client (user PC), and domestic or foreign DRM companies do not go beyond the limitation. That is, due to the factors such as limited resources of a user PC, unstable factors of software, OS version upgrade, incompatibility among devices and the like, there are a lot of problems such as difficulties in compatibility among different types of OSs or mobile devices, difference of performance according to the environment of a connecting user, occurrence of error in software, increase of factors threatening security accompanied by using Active-X, and the like. In addition, since the existing E-DRM security techniques are not standardized due to the competition of technical skills among the companies, products of the manufacturing companies are not compatible with one another, and thus a different program needs to be separately installed for each company. Therefore, performance of the user PC is lowered since the programs installed in the user PC collide and interfere with one another. In addition, since each of the programs provides a different user interface, users suffer from inconvenience and increased work load, and from the viewpoint of the enterprise, burdens such as cost and the like are increased.
Meanwhile, advancement in the network environment, including improvement of the Internet speed, changes computer systems and the methods using the computer systems. That is, one of the changes is the advent of clouding computing which integrates resources of computers existing at different physical locations and provides the integrated resources. The resources are integrated through a virtualization technique by using servers having powerful functions, which are connected through a network, or by remotely using software. The cloud computing includes a system cloud used for parallel distributed data processing using a plurality of systems connected through a network and a service cloud for performing an operation or control process by a central server in response to a request from a plurality of clients or sharing integrated data among a variety of devices. Through the cloud computing methods, users may use the cloud computing service through the Internet at any place only if they carry a terminal having an Internet connection function and basic operation functions.